table {
  border: 1px dashed red;
  width: 100%;
  /* 分割 */
  /* border-collapse: separate; */
  /* border-spacing: 10px; */
  border-collapse: collapse;
  /* 表格单元格宽度固定模式 */
  table-layout: fixed;
}

td {
  border: 1px solid blue;
}

thead th:nth-of-type(1) {
  width: 10%;
}

thead th:nth-of-type(2) {
  width: 20%;
}

thead th:nth-of-type(3) {
  width: 40%;
  text-align: left;
}

thead th:nth-of-type(4) {
  width: 30%;
}
